Apparatus for projecting circular markings upon nonplanar surfaces



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Feb 21, 1950 Y J. G.`ARN0LD ET AL PPRATUS FOR PROJECTING CIRCULAR MARKINGS UFN' NONPLANAR SURFACES Filed June l2, 1944 Feb. 2l, 1950,

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Feb. 21, 1950 J. G. ARNOLD ETAL 2,497,853

APPARATUS FOR PROJECTING CIRCULAR MARKINGS UPON NONPLANAR sURFAcEs :s sneetssheet s Filed' Jun-e 112( 1944 f nu Patented Feb. 21, 1950 APPARATUS FOR PROJECTING CIRCULAR MARKINGS UPON NONPLANAR SURFACES Joseph G. Arnold, Chicago, Ill., and William C. Piggott, Port Arthur, Tex., assignors to Chicago Bridge & lron Company, a. corporation of Illinois Application June 12, 1944, Serial No. 539,980

This invention relates to a method of projecting circular markings upon inclined or multiplanar surfaces, such, for example, as spheroids, for the purpose of forming an opening adapted to ilt cylindrical pipes and the like.

The invention is particularly applicable to the manufacture of steel tanks having spheroidal, conical, or other multiplanar surfaces. In the past whenever it was necessary to t a pipe into such a surface, the projection of the circular pipe upon the irregular work surface was made by trial and error or by rough approximation. The result was that fittings were not exact. The invention may also be applied to flat surfaces where the pipe is to be at an angle thereto.

We have discovered that accurate positioning and location of such openings may readily be made on multiplanar surfaces by aixing a control arm to the work surface at the point where the axis of the tting cylinder impinges upon i the surface and in the same position that the axis of the cylinder is to occupy. A marking arm is held in spaced radial relationship to the control arm by at least one spacing member which is slidably mounted. The marking arm is then rotated while in marking contact with the work surface. Since it is held in fixed radial relationship to the control arm but is free to move inwardly and outwardly along, or with respect to, the control arm, it will mark the proper projection of a circle upon the work surface.

The invention is illustrated in the drawings in which Figure 1 is a plan view of one form of the apparatus in position upon a Work surface;

Figure 2 is a similar view of a modified form of the device; Figure 3 is a view of a Work surface with the pipe fitted in the opening produced by the present invention; Figure 4 is a side view of the lug; and Figure 5 is a View of a modified form of the invention.

As shown in the drawings, the Work surface I0, which may be a spheroidal segment of a sheet metal tank, is to be provided with an opening for a pipe II in the angular position shown in Figure 3. In order to produce this opening a lug I2 is Welded to the work surface near the point I3 at which the axis of the pipe I I impinges upon it. The lug I2 may suitably be of the form shown in Figure 4 consisting of an tip-standing metal web I4 having a lock opening I5. control arm I6 is preferably pointed, as at I1, and the point is placed at the point I3 and the arm itself is held in the same angular relationship to the work surface that the pipe II is to occupy. A stud I8 is provided on the control 1 Claim. (Cl. 33-21) lil 2 arm having a threaded neck I9 which fits within the lock opening I5. A Wing nut 20 is provided for locking the control arm in position.

A movable ring clamp 2l is provided on the control arm as a stop. Beyond it is a slidable tube 22 fitting loosely upon the arm and held upon the arm by a stop 23. The tube 22 carries plates 24 and 25 having threaded studs 26 and 21 carrying the wing nuts 28 and 29. Adjustable spacing members or radius arms 3B and 3l having slots 32 and 33 are positioned upon the studs 26 and 21 and also secured to a tube 34 within which the marking arm 35 is slidably mounted. A set screw 36 is provided in the tube 34 for fixing the arm in a predetermined position if desired. It is obvious that the radius arms and the marking arm may be consolidated as a unit, provided that the assembly is slidable on the control arm, butin that case the end of the marking arm, including the marker, should be parallel to the control arm for accuracy.

The marking arm is shown in Figure 1 as pro-V vided with a marker 31 which may preferably be a piece of soapstone. This is held in position by any suitable means. l

In carrying out the operation the lug I2 is secured to the work surface, and the control arm is then fixed in axial alignment with the axis to be occupied by the pipe. It is preferred that the point I1 of the control arm be positioned directly upon the work surface. The control arm may be axially aligned with that of the pipe without contacting the Work surface and even Without any direct attachment thereto, but this involves difficulty such that it is preferred to attach the arm directly to the work surface. The spacing members 30 and 3| are then adjusted to the proper radius. The marking arm is then rotated with the marker in marking contact with the Work surface. Inasmuch as the marking arm may slide within the tube 34, it will mark a projection of a circle upon the Work surface. The same result may be obtained by fixing the marking arm in the tube 34 and sliding the tube 22 on the control arm. This, however, is generally less suitable because of the added mechanism which must be moved. With the marking arm free to move in the tube 34, the only inertia to be overcome is that of the arm itself. If the marking arm is slidable with respect to the radius arms, it should be parallel to the control arm.

In Figure 2 We have shown another form of the invention in which the marking device is a blcwtorch 40. In this case the flame from the torch is directed axially of the marking arm so that the distance of the torch itself from the work is unimportant. The arm is rotated in marking contact with the work surface-i. e., with the ilame from the torch bearing upon the work surface. Theil torch may; heused'to mark'or. to cut the Work; Other cutting means may be substituted if desired.

The blowtorch is carried in a yoke 4I detachably secured to the lower end 42; of; the marking arm 35. The hoses 43 and 4i4 of the blowtorch are looped and secured to the tube 22. In view of the Weight of the blowtorch, we have indicatedV a support 45 secured to theouter'end4 46 of' the control arm and to the work surface at 4l.

In Figure 5 we have shown a modied form of the device in which a universal mounting. 601 is provided which may be welded or secured. either to the work surface or elsewhere. This mount'- ing includes a base 6| having a pair of upright arms i2in'whi'ch the yoke is rotatably'mounted as, for example; upon the pin E4. In the upper part of theA yoke is apin 65 upon'which'is mounted' the curved arm 66. The movement ofthis arm isl limited by the pin 61 provided with the wing nut 68; Thispinis positioned in the slot 69 in the yoke 63; The arm 66 has a lateral extension 'IU having aV` length more-than half that of the largest opening,` which it is' proposed to make. Inv the end of the extension is a circular enlarge-l ment 'H having a central opening 'I2 through which the control arm 13 is passed; The point 114 of the control arm is` set at the predetermined position on the workV surface'.

A sleeve 1-5 carries theradius arms 1S and 11 which are suitably` calibrated' as indicated atA 18' to indicate the'measured radius. Each of these arms is made up of'a pair of'bars19` and 89', telescoping withinI 'I9 orb'eing otherwise suitably carried'v thereby; A' set screw-A 8| may be provided' for locking them iii-position. The motion of the sleeve 15 on the control arm 'I3-is suitablyliinited by t-he adjustableStop 82'.

Theradius' arms terminate'irr a sleeve 83 within which the marking arm 841is' positioned. To

the lower portion of this arm is secured a. bar to which the blowtorch 86 is fastened.

The foregoing detailed description has been given for clearness of understanding only, and no unnecessary limitations should be understood therefrom..

Whatwe claim as new; and desire to secure by Letters Patent, is:

Apparatus for determining an opening in a work surfaceinztheshape of a non-circular projection of ai predetermined circle comprising: a control arm, means secured to said control arm adapted to: be weldedA to said Work surface for rigidly securing, the control arm to the surface in a predetermined. angular position over a point on said surface at the center of said circle, a marking arm, a rst tubular member slidably androtatably mounted on said control arm, stop means on said control arm to limit the slidable movement of said member, a second tubular membei" slidabl'ymounted on said'. marking arm and rotatable relative thereto, a pair of adjustable arms.` secured to said' members: for radially spacing the marking* arm varying predeterminedv distances from the -control arm whereby said marking arm is rotatable about said control arm and is slidabley in said second tubular member in a direction axially of said control arm while in marking Contact; withr said surface.

` JOSEPH G. ARNOLD;

WILLIAM C. PIGGOTT.

REFERENCES CITED- The following referencesare. of` record in the le of: thispatent:

UNITED STATES PATENTSA Number Name Date 1,286,770 Rashkovsky Dec. 3,. 1918 1,991,117 Porteous. et al .Feb. l2, 1935. 2,142,436 Clabeaux Jan. 3,. 1939 FOREIGN. PATENTS Number Country Date 545,026 Germany Feb. 25, 1932 

